Process for the production of alkyl



Reissued July 12, 1955 PROCESS FOR THE PRODUCTION OF ALKYL AROMATIC HYDROPEROXIDES Michel Marius Mosnier and Andre Fournet, Lyon, France,

asslgnors to Societe des Uslnes Chlmlques Rhone- Poulenc, Paris, France No Drawiu Original No. 2,681,937, dated June 22,

1954, Se i No. 268,682, January 28, 1952. A lieutlon for reissue February 14, 1955, Serial No. 4 ,178

12 Claims. (Cl. 260-610) Matter enclosed in heavy brackets appears in the original patent but forms no art of s reissue eciiication; matter printed in ita cs indicates the ad tlons made by reissue.

This invention is for improvements in or relating to the production of the hydroperoxides of cumene and its homologues. More particularly, this invention is concerned with the conversion of cumene and homologous alkyl-aromatic hydrocarbons into the corresponding hydroperoxides by oxidation. According to the literature, this oxidation can be eifected with excellent yield by treatment of the hydrocarbon with oxygen at 85 C.

it is an object of the present invention to speed up the aforesaid oxidation reaction without detriment to the yield or quality of the desired oxidation product by employing a novel catalyst for the reaction. Further objects will appear from the following description.

According to the present invention, the oxidation of curnene and other homologous alkyl-aromatic hydrtr carbons such as p-cymene, di-isopropyl benzene, isobutyl benzene (i. e. a-methyl-n-propyl benzene) and ethyl benzene by means of oxygen or an oxygen-containing gas such as air, is effected in the presence as catalyst of a member of the class consisting of alkali and alkaline-earth metal formates, oxalates and benzeates.

The proportion of catalyst employed may vary within fairly wide limits depending to some extent upon the operating conditions chosen, the optimum amount being determinable by simple preliminary test. It is usually advantageous to introduce the catalyst in pottions during the course of the operation.

The oxidation of the aforesaid hydrocarbons in the presence of a catalyst in accordance with the present invention is preferably carried out under the conditions generally adopted heretofore in the preparation of the hydroperoxides of hydrocarbons. More especially, and in conformity with a common practice in oxidation of this nature, there may be added at the very commencement of the process a small quantity of a hydroperoxide for the purpose of initiating the reaction. This hydroperoxide may be, for example, the hydroperoxide of the hydrocarbon to be oxidised, obtained from a prior operation.

The following examples illustrate methods of carrying the invention into effect.

EXAMPLE I 220 litres of air per hour are passed under a pressure of 12 kg. and at a temperature of 110 C. into 2700 cc. of cumene, to which 68 g. of pure cumene hydroperoxide have been added in order to initiate the reaction. in a parallel experiment, 2 g. of finely divided sodium formats are added at the commencement, and a further 1 g. thereof is added at the end of each successive hour.

A small sample is taken every hour, and the hydroperoxide titer is determined therefrom by iodometry.

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The results are given in the following table, which shows the weights expressed in grams per 100 cc. of cumene hydroperoxide present at a given time (column A) and former per hour (column B) respectively.

Experiment with- Experiment with out tomato formats Reaction Time in Hours A B A B It will be seen from the foregoing table that, in the same period of time, three times as much hydroperoxide is obtained in the presence of formate as in the absence of formats. It will also be noted that the hourly production without formate reaches a maximum of 2.85% after one hour and falls to 0.71% at the fifth hour, whereas in the presence of formate the hourly production is 4.84% at the end of the first hour and progressively increases to 8.26% at the end of the fifth hour.

If the respective purities of the hydroperoxldc ob tained for substantially corresponding yields, that is to say, for example, after five hours without formats and after two hours with formate, are compared by determination of the percentage of by-products obtained, it is found that the product prepared without formats has a purity of 91.4%, that is to say, it contains 8.6% of by-products, while the product obtained with formate has a purity of 94%, that is to say it contains only 6% of by-products.

EXAMPLE Ii ments:

Experiment with- Experiment with out formats formats Reaction Time in Hours A B A B 0.. 3. 2 a. 2 1. 5. 3 2. 0 5. 7 2. 5 2. 0. 7 l. 4 8. 0 2. 3 L B. 0 1. 0 l0. 7 2. 7 i 10. 4 1.8 it. 3 3. B i 12. 5 2. 1 18. 0 3. 7 t 14. 2 1.7 22. B 4. 8 16. 0 1. B 27. b 4. 0 i..- 17. 8 1. 8 t 19. 5 1.7 21. i 1. 0 22. i 1. 0 23.1 .07

The hourly average yield in the experiment without formate is 1.66%, while the average yield in the presence of formate attains 3.47%.

The purity of the hydroperoxide obtained without formate after twelve hours is 86%, while in the presence of formats it is 93% after seven hours. it will, therefore, be seen that for a product prepared in the presence of sodium formate a purer product, containing half the quantity of by-products, was obtained in scarcely more than half the time.

3 EXAMPLE III The operation of Example I is repeated, but with oxygen instead of air. In the experiment with sodium formate, 2 g. are added at the start, and a further 1 g. is

tion, prepared in the presence of calcium formate, is 93%.

EXAMPLE VI 220 litres of air are bubbled under a pressure of 12 kg.

added after the end of the first and second hours respecinto 2700 cc. of cumene heated at 110 C., to which 68 tively and a further 0.5 g. at the end of every successive g. of cumene hydroperoxide have been added in order to hour thereafter. Supply of oxygen 60 litres per hour. eliminate the period of induction.

A first experiment, in which no other addition is made, Experiment with- Experiment wi will serve for reference purposes. Mm Tim m Hum In a second experiment, 1 g. of finely divided sodium oxalate is added at the commencement and a further 1 g. A B A B is added after the end of each of the first three hours.

In a third experiment, 2 g. of finely divided calcium oxalate are added at the commencement, a further 1 g. 114 1Is sis as after the end of the first and second hours and a further 3-5 0.5 g. after the end of the third and fourth hours, respecisl 1 11 7 asI a' 1 tively.

1:: In a fourth experiment, 2 g. of finely divided sodium 11.2 1.1 no benzoate are added at the commencement and a further 5 g. after each of the first four hours, respectively.

The average hourly yield without formate is 1.74% and A small sample is taken every hour, and the hydrowith formate 5.59%. peroxide titer is determined therefrom by iodometry.

The purity of the hydroperoxide of the 17.2% solution At the end of the experiment, unchanged cumene is obtained after 8 hours without formate is 90.5%, and the mo End the hydroperoxide liter of the Product purity of the hydroperoxide of the 20.1% solution obtained is determined. The complement to 100 of the tained after 4 hours with formate (chosen to provide a figure thus obtained indicates the percentage of bymore accurate comparison) is 93.5%. Therefore, for a pr immedcomparable proportion of hydroperoxide, 50% more of Thc fault! Given in the followins 1351:, the 185! by-products were btained in the absence of i m t lines of which indicate the purity of the hydroperoxide EXAMPLE Iv obtained and the percentage of by-products.

In this example, the cumene is employed in the form without with ,odmm wmhmdmm of a suspension in water. 827 parts of cumene, 51.5% m m W11! 0mm 0mm 11mm parts of a 35.5% solution of cumene hydroperoxide in cumene and 1000 parts of water (all the parts being parts A B A B A B A B by volume) are introduced into the oxidation vessel. The operation is carried out at 85 C. and eleven parts by g: ,?f 3:; volume of oxygen per hour are introduced. The quantity 917 31a 1 1 u u of sodium formate added corresponds to 1.5% of the it: $3 3': &g 8:: water added. ztIo 411 27.3 sla sat 1.0

32.'."i3?iii.li"' arsa 1% "2;?" 31% Reactlon 'Ilma in Hours r A B A B 0 It will be seen from this table, that, in the presence of the catalysts, the speed of oxidation is from two to 2.3 2.3 three times the speed obtained without catalyst, and 1 3 g 33 if that the quantity of by-products is smaller than is the 3 5 3 13: case in the experiment without catalyst. EXAMPLE VII The hourly yield of hydroperoxide without formate is 0.71% and with sodium formate it is 1.13%.

The purity of the product obtained without formate is 90% and that of the product obtained in the presence of formate is 91.5%.

EXAMPLE V The operation is the same as in Example III but the sodium formate is replaced by the same quantities of calcium formate.

The average hourly yield without formate is 1.74%, and in the presence of calcium formate it is 4%.

The purity of the product prepared without formate is 90%. The purity of the product of twice the concentra- 600 cc. of p-cymene containing 5 g. of 68% p-cymene hydroperoxide to eliminate the period of induction are mixed with 3 g. of sodium formate. 20 litres of oxygen per hour are passed at 120 C. into the liquid for seven hours. A solution of p-cymene containing 16% of p-cymene hydroperoxide is obtained. The small quantity of iaopropylbenzoic acid simultaneously formed during the oxidation is separated by washing with a dilute solution of sodium carbonate. The yield of p-cymene hydroperoxide is from to calculated on the weight of p-cymene consumed, the remaining percentage consisting of isopropylbenzoic acid, dimethyl-p-methylphenylcarbinol and p-methylacetophenone.

EXAMPLE VIII Into 250 cc. of a-methyl-n-propyl benzene containing 5 g. of a-methyl-n-propyl benzene hydroperoxide and 1 g. of sodium formate are passed 10 litres of oxygen per hour at C. for 17 hours. A 14.9% solution of a-methyl-mpropyl benzene hydroperoxide in alt-methyln-propyl benzene is obtained.

The yield of hydroperoxide is from 80% to 85% calculated on the quantity of a-methyl-n-propyl benzene consumed.

We claim:

I. Process for the production of alky ar matic by droperoxides by the oxidation of cumene and omoi gous alkylaromatic hydrocarbons in which at least one alkyl substituent [group is a tertiary alkyl group and contains more than one carbon chain, the tertiary carbon atom eing attached directly] containing more than 2 carbon atoms has one hydrogen atom attached to the carbon atom which is directly attached to the aromatic nucleus, which comprises bringing the said hydrocarbon into contact with oxygen at elevated temperature in the presence of a catalyst selected from the class consisting of the formates, oxalates and benzoates of the alkali metals and alkaline earth metals.

2. Process for the production of alkyl-aromatic hydroperoxides which comprises bringing a member of the class consisting of cumene, p-cymene, di-isopropyl benzene and m-methyl-n-propyl benzene into contact with oxygen at elevated temperature in the presence of a catalyst selected from the class consisting of the formates, oxalates anad benzoates of the alkali metals and alkaline earth metals and in the presence of a hydroperoxide.

3. Process for the production of alkyl-aromatic hydroperoxides by the oxidation of cumene and homologous alkyl-aromatic hydrocarbons in which at least one alkyl substituent [group is a tertiary alkyl group and contains more than one carbon atom, the tertiary carbon atom being attached directly] containing more than 2 carbon atoms has our hydrogen atom attached to the carbon atom which is directly attached to the aromatic nucleus, which comprises bringing the said hydrocarbon into contact with oxygen at elevated temperature in the presence of sodium formate as catalyst.

4. Process for the production of alkyl-aromatic hydroperoxides by the oxidation of cumene and homologous alkyl-aromatic hydrocarbons in which at least one alkyl substituent [group is a tertiary alkyl group and contains more than one carbon atom, the tertiary carbon atom eing attached directly] containing more than 2 carbon Moms has one hydrogen atom attached to the carbon atom which is directly attached to the aromatic nucleus. which comprises bringing the said hydrocarbon into conact with oxygen at elevated temperature in the presence f calcium formats as catalyst.

5. Process for the production of alkyl-aromatic hydroperoxides by the oxidation of cumene and homologous alkyl-aromatic hydrocarbons in which at least one alkyl ubstitucnt [group is a tertiary alkyl group and contains more than one carbon atom, the tertiary carbon atom e ng attached directly] containing more than 2 carbon atoms has one hydrogen atom attached to the carbon atom which is directly attached to the aromatic nucleus, wh ch comprises bringing the said hydrocarbon into ontact with oxygen at elevated temperature in the pres nce of sodium oxalate as catalyst.

6. Process for the production of alkyl-aromatic hydroperoxides by the oxidation of cumene and homologous alkyl-aromatic hydrocarbons in which at least one alkyl substituent [group is a tertiary alkyl group and contains more than one carbon atom, the tertiary carbon atom being attached directly] containing more than 2 carbon atoms has one hydrogen atom attached to the carbon atom which is directly attached to the aromatic nucleus, which comprises bringing the said hydrocarbon into contact with oxygen at elevated temperature in the presence of calcium oxalate as catalyst.

7. Process for the production of alkyl-aromatic hydroperoxides by the oxidation of cumene and homologous alkyl-aromatic hydrocarbons in which at least one alkyl substituent [group is a tertiary alkyl group and contains more than one carbon atom, the tertiary carbon atom being attached directly] containing more than 2 carbon atoms has one hydrogen atom attached to the carbon atom which is directly attached to the aromatic nucleus, which comprises bringing the said hydrocarbon into contact with oxygen at elevated temperature in the presence of sodium benzoate as catalyst.

8. Process for the production of alkyl-aromatic hydroperoxides which comprises bringing a member of the class consisting of cumene, p-cymene, di-isopropyl benzene and a-methyl-n-propyl benzene into contact with oxygen at elevated temperature in the presence of a hydroperoxide and of sodium formats as catalyst.

9. Process for the production of alkyl-aromatic hydroperoxides which comprises bringing a member of the class consisting of cumene, p-cymene, di-isopropyl benzone and a-methyl-n-propyl benzene into contact with oxygen at elevated temperature in the presence of a hydroperoxide and of calcium formate as catalyst.

10. Process for the production of alkyl-aromatic hydroperoxides which comprises bringing a member of the class consisting of cumene, p-cymene, di-isopropyl benzene and wmethyl-n-propyl benzene into contact with oxygen at elevated temperature in the presence of a hydroperoxide and of sodium oxalate as catalyst.

11. Process for the production of alkyl-aromatic hydroperoxides which comprises bringing a member of the class consisting of cumene, p-cymene, di-isopropyl ben zene and a-methyl-n-propyl benzene into contact with oxygen at elevated temperature in the presence of a hydroperoxide and of calcium oxalate as catalyst.

12. Process for the production of alkyl-aromatic hydroperoxides which comprises bringing a member of the class consisting of cumene, p'cymene, di-isopropyl benzene and a-methyl-n-propyl benzene into contact with oxygen at elevated temperature in the presence of a hy droperoxide and of sodium benzoate as catalyst.

Hall et al. Apr. 10, 1951 Lorand et al. Apr. 10. I951 

